What process occurs as new layers of sediment are added to old layers of sediment, causing pressure on the older layers?
•weathering
•erosion
•cementation
•deposition

do you have a picture?

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.

when it is at an intermediate population density

i wish i could with all of them i can barley see the first one so here's the answer to the first one b